On Tue, Jan 30, 2024 at 05:30:38PM +0800, kernel test robot wrote:
> Hi Vincent,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on 29142dc92c37d3259a33aef15b03e6ee25b0d188]
>
> url:
> https://github.com/intel-lab-lkp/linux/commits/Vincent-Donnefort/ring-buffer-Zero-ring-buffer-sub-buffers/20240129-223025
> base: 29142dc92c37d3259a33aef15b03e6ee25b0d188
> patch link:
> https://lore.kernel.org/r/20240129142802.2145305-4-vdonnefort%40google.com
> patch subject: [PATCH v13 3/6] tracing: Add snapshot refcount
> config: arc-randconfig-002-20240130
> (https://download.01.org/0day-ci/archive/20240130/202401301740.qzzlpcyv-...@intel.com/config)
> compiler: arceb-elf-gcc (GCC) 13.2.0
> reproduce (this is a W=1 build):
> (https://download.01.org/0day-ci/archive/20240130/202401301740.qzzlpcyv-...@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version
> of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <l...@intel.com>
> | Closes:
> https://lore.kernel.org/oe-kbuild-all/202401301740.qzzlpcyv-...@intel.com/
>
> All errors (new ones prefixed by >>):
>
> kernel/trace/trace.c: In function 'tracing_set_tracer':
> kernel/trace/trace.c:6644:17: error: implicit declaration of function
> 'tracing_disarm_snapshot_locked'; did you mean 'tracing_disarm_snapshot'?
> [-Werror=implicit-function-declaration]
> 6644 | tracing_disarm_snapshot_locked(tr);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | tracing_disarm_snapshot
> >> kernel/trace/trace.c:6648:23: error: implicit declaration of function
> >> 'tracing_arm_snapshot_locked'; did you mean 'tracing_arm_snapshot'?
> >> [-Werror=implicit-function-declaration]
> 6648 | ret = tracing_arm_snapshot_locked(tr);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> | tracing_arm_snapshot
> cc1: some warnings being treated as errors
Right, two tracers (hwlat and osnoise) select _only_ MAX_TRACE and not
TRACER_SNAPSHOT.
However, AFAICT, they will not call any of the swapping functions (they don't
set use_max_tr). So I suppose arm/disarm can be ommited in that case.
>
>
> vim +6648 kernel/trace/trace.c
>
> 6560
> 6561 int tracing_set_tracer(struct trace_array *tr, const char *buf)
> 6562 {
> 6563 struct tracer *t;
> 6564 #ifdef CONFIG_TRACER_MAX_TRACE
> 6565 bool had_max_tr;
> 6566 #endif
> 6567 int ret = 0;
> 6568
> 6569 mutex_lock(&trace_types_lock);
> 6570
> 6571 if (!tr->ring_buffer_expanded) {
> 6572 ret = __tracing_resize_ring_buffer(tr,
> trace_buf_size,
> 6573
> RING_BUFFER_ALL_CPUS);
> 6574 if (ret < 0)
> 6575 goto out;
> 6576 ret = 0;
> 6577 }
> 6578
> 6579 for (t = trace_types; t; t = t->next) {
> 6580 if (strcmp(t->name, buf) == 0)
> 6581 break;
> 6582 }
> 6583 if (!t) {
> 6584 ret = -EINVAL;
> 6585 goto out;
> 6586 }
> 6587 if (t == tr->current_trace)
> 6588 goto out;
> 6589
> 6590 #ifdef CONFIG_TRACER_SNAPSHOT
> 6591 if (t->use_max_tr) {
> 6592 local_irq_disable();
> 6593 arch_spin_lock(&tr->max_lock);
> 6594 if (tr->cond_snapshot)
> 6595 ret = -EBUSY;
> 6596 arch_spin_unlock(&tr->max_lock);
> 6597 local_irq_enable();
> 6598 if (ret)
> 6599 goto out;
> 6600 }
> 6601 #endif
> 6602 /* Some tracers won't work on kernel command line */
> 6603 if (system_state < SYSTEM_RUNNING && t->noboot) {
> 6604 pr_warn("Tracer '%s' is not allowed on command
> line, ignored\n",
> 6605 t->name);
> 6606 goto out;
> 6607 }
> 6608
> 6609 /* Some tracers are only allowed for the top level
> buffer */
> 6610 if (!trace_ok_for_array(t, tr)) {
> 6611 ret = -EINVAL;
> 6612 goto out;
> 6613 }
> 6614
> 6615 /* If trace pipe files are being read, we can't change
> the tracer */
> 6616 if (tr->trace_ref) {
> 6617 ret = -EBUSY;
> 6618 goto out;
> 6619 }
> 6620
> 6621 trace_branch_disable();
> 6622
> 6623 tr->current_trace->enabled--;
> 6624
> 6625 if (tr->current_trace->reset)
> 6626 tr->current_trace->reset(tr);
> 6627
> 6628 #ifdef CONFIG_TRACER_MAX_TRACE
> 6629 had_max_tr = tr->current_trace->use_max_tr;
> 6630
> 6631 /* Current trace needs to be nop_trace before
> synchronize_rcu */
> 6632 tr->current_trace = &nop_trace;
> 6633
> 6634 if (had_max_tr && !t->use_max_tr) {
> 6635 /*
> 6636 * We need to make sure that the update_max_tr
> sees that
> 6637 * current_trace changed to nop_trace to keep
> it from
> 6638 * swapping the buffers after we resize it.
> 6639 * The update_max_tr is called from interrupts
> disabled
> 6640 * so a synchronized_sched() is sufficient.
> 6641 */
> 6642 synchronize_rcu();
> 6643 free_snapshot(tr);
> 6644 tracing_disarm_snapshot_locked(tr);
> 6645 }
> 6646
> 6647 if (t->use_max_tr) {
> > 6648 ret = tracing_arm_snapshot_locked(tr);
> 6649 if (ret)
> 6650 goto out;
> 6651 }
> 6652 #else
> 6653 tr->current_trace = &nop_trace;
> 6654 #endif
> 6655
> 6656 if (t->init) {
> 6657 ret = tracer_init(t, tr);
> 6658 if (ret) {
> 6659 #ifdef CONFIG_TRACER_MAX_TRACE
> 6660 if (t->use_max_tr)
> 6661
> tracing_disarm_snapshot_locked(tr);
> 6662 #endif
> 6663 goto out;
> 6664 }
> 6665 }
> 6666
> 6667 tr->current_trace = t;
> 6668 tr->current_trace->enabled++;
> 6669 trace_branch_enable(tr);
> 6670 out:
> 6671 mutex_unlock(&trace_types_lock);
> 6672
> 6673 return ret;
> 6674 }
> 6675
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
